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UNITED STATES DEPARTMENT OF AGRICULTURE 

 BULLETIN No. 460 



Contribution from the Forest Service 

 HENRY S. GRAVES, Forester 



Washington, D. C. 



PROFESSIONAL PAPER 



THE PINE TREES 

 OF THE ROCKY MOUNTAIN REGION 



By 

 GEORGE B. SUDWORTH, Dendrologist 



CONTENTS 



Page 



Scope of Bulletin 1 



Generic Characteristics of Pines: 

 White Pines: 



Western White Pine (Pinu* 



monticola Douglas) .... 4 

 Limber Pine (Pinua flexilia 



James) 7 



White-Bark Pine {Pinua albi- 



caulis Engelmann ) . . , . 9 

 Mexican White Pine (Pinua atro- 



bi for mis Engelmann) ... 12 

 Mexican Piflon (Pinus cernbro- 



tdes Zuccarini ) 15 



Piflon; Nut Pine (Pinus edulis 



Engelmann) . 18 



Single-Leaf Pine ( Pinua mono- 



phylla Torre y and Fremont ) . 21 

 Bristle-Cone Pine (Pinua aria- 

 tat a Engelmann) 23 



Pag» 

 Generic Characteristics of Pines— Con. 

 Yellow Pines: 



Arizona Pine (Pinua arizonica 



Engelmann) 26 



Western Yellow Pine (Pinua 



ponderoaa Lawson ) . . . . 



Apache Pine; "Arizona Longleaf 



Pine " (Pinua apacheca Lem- 



mon) 



Chihuahua Pine (Pinua chihu- 



ahuana Engelmann) , . . . 



LodgepoIePine (Pinua contorta 



Loudon) 38 



Jack Pine (Pinua bankaiana 



Lambert) 42 



Key to Species 46 



28 



33 



36 



WASHINGTON 

 GOVERNMENT PRINTING OFFICE 



1917 



